/* eslint-disable es/no-block-scoped-variables */
// https://cs.nyu.edu/~perlin/noise/

const _p = [151, 160, 137, 91, 90, 15, 131, 13, 201, 95, 96, 53, 194, 233, 7, 225, 140, 36, 103, 30, 69, 142, 8, 99, 37, 240, 21, 10,
    23, 190, 6, 148, 247, 120, 234, 75, 0, 26, 197, 62, 94, 252, 219, 203, 117, 35, 11, 32, 57, 177, 33, 88, 237, 149, 56, 87,
    174, 20, 125, 136, 171, 168, 68, 175, 74, 165, 71, 134, 139, 48, 27, 166, 77, 146, 158, 231, 83, 111, 229, 122, 60, 211,
    133, 230, 220, 105, 92, 41, 55, 46, 245, 40, 244, 102, 143, 54, 65, 25, 63, 161, 1, 216, 80, 73, 209, 76, 132, 187, 208,
    89, 18, 169, 200, 196, 135, 130, 116, 188, 159, 86, 164, 100, 109, 198, 173, 186, 3, 64, 52, 217, 226, 250, 124, 123, 5,
    202, 38, 147, 118, 126, 255, 82, 85, 212, 207, 206, 59, 227, 47, 16, 58, 17, 182, 189, 28, 42, 223, 183, 170, 213, 119,
    248, 152, 2, 44, 154, 163, 70, 221, 153, 101, 155, 167, 43, 172, 9, 129, 22, 39, 253, 19, 98, 108, 110, 79, 113, 224, 232,
    178, 185, 112, 104, 218, 246, 97, 228, 251, 34, 242, 193, 238, 210, 144, 12, 191, 179, 162, 241, 81, 51, 145, 235, 249,
    14, 239, 107, 49, 192, 214, 31, 181, 199, 106, 157, 184, 84, 204, 176, 115, 121, 50, 45, 127, 4, 150, 254, 138, 236, 205,
    93, 222, 114, 67, 29, 24, 72, 243, 141, 128, 195, 78, 66, 215, 61, 156, 180];

for (let i = 0; i < 256; i++) {

    _p[256 + i] = _p[i];

}

function fade(t) {

    return t * t * t * (t * (t * 6 - 15) + 10);

}

function lerp(t, a, b) {

    return a + t * (b - a);

}

function grad(hash, x, y, z) {

    const h = hash & 15;
    const u = h < 8 ? x : y, v = h < 4 ? y : h == 12 || h == 14 ? x : z;
    return ((h & 1) == 0 ? u : - u) + ((h & 2) == 0 ? v : - v);

}

function noise(x, y, z) {

    const floorX = Math.floor(x), floorY = Math.floor(y), floorZ = Math.floor(z);

    const X = floorX & 255, Y = floorY & 255, Z = floorZ & 255;

    x -= floorX;
    y -= floorY;
    z -= floorZ;

    const xMinus1 = x - 1, yMinus1 = y - 1, zMinus1 = z - 1;

    const u = fade(x), v = fade(y), w = fade(z);

    const A = _p[X] + Y, AA = _p[A] + Z, AB = _p[A + 1] + Z, B = _p[X + 1] + Y, BA = _p[B] + Z, BB = _p[B + 1] + Z;

    return lerp(w, lerp(v, lerp(u, grad(_p[AA], x, y, z),
        grad(_p[BA], xMinus1, y, z)),
        lerp(u, grad(_p[AB], x, yMinus1, z),
            grad(_p[BB], xMinus1, yMinus1, z))),
        lerp(v, lerp(u, grad(_p[AA + 1], x, y, zMinus1),
            grad(_p[BA + 1], xMinus1, y, zMinus1)),
            lerp(u, grad(_p[AB + 1], x, yMinus1, zMinus1),
                grad(_p[BB + 1], xMinus1, yMinus1, zMinus1))));

}